My Savage makes exactly the same sound. I think it's the sound of exhaust valves ticking. No matter how I adjust the valves, it's always the same. It was the same before and after I replaced the cam chain. Could be that I have a bad valve cover gasket, or bad connection between the exhaust and the engine, and I can hear it from there.
As for the smoke... well, it does that too sometimes
Usually that means I have an oil leak (speedo cable is my usual suspect) and the oil drips on the hot exhaust. After riding, some oil from the leak will gradually drip on the cold exhaust and stay there, until it warms up again, so there is a bigger cloud. When riding it just burns up drop by drop, so there is less smoke.
The motorcycle is from 1998. I run 20W50 mineral oil, but it was the same on 10W40. I get MPG from 40 in town to 50-55 on a highway.
As for the oil consumption, It was recently about 200 ml per 200 miles, but I just fixed two leaks (oil filler cap, and speedo cable), so maybe it'll get a bit better now...